From c6ddb9cedb56c4b291c394f6e988849f93b4c877 Mon Sep 17 00:00:00 2001
From: Mike McQuaid <mike@mikemcquaid.com>
Date: Mon, 19 Aug 2024 09:17:21 +0100
Subject: [PATCH] brew.sh: hide ignorable permission errors.

`GIT_DESCRIBE_CACHE` is a performance optimisation that doesn't clean
up consistently when run with different Homebrew users. Instead of
doing user detection: let's just hide these errors that we don't care
about.

Reported in:
https://github.com/orgs/Homebrew/discussions/5479
---
 Library/Homebrew/brew.sh | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/Library/Homebrew/brew.sh b/Library/Homebrew/brew.sh
index c62896ba00..959d86149e 100644
--- a/Library/Homebrew/brew.sh
+++ b/Library/Homebrew/brew.sh
@@ -446,10 +446,13 @@ then
   then
     HOMEBREW_VERSION="$(cat "${GIT_DESCRIBE_CACHE_FILE}")"
   else
-    rm -rf "${GIT_DESCRIBE_CACHE}"
     HOMEBREW_VERSION="$("${HOMEBREW_GIT}" -C "${HOMEBREW_REPOSITORY}" describe --tags --dirty --abbrev=7 2>/dev/null)"
-    mkdir -p "${GIT_DESCRIBE_CACHE}"
-    echo "${HOMEBREW_VERSION}" >"${GIT_DESCRIBE_CACHE_FILE}"
+    # Don't output any permissions errors here.
+    # The user may not have write permissions to the cache but we don't care
+    # because it's an optional performance improvement.
+    rm -rf "${GIT_DESCRIBE_CACHE}" 2>/dev/null
+    mkdir -p "${GIT_DESCRIBE_CACHE}" 2>/dev/null
+    echo "${HOMEBREW_VERSION}" >"${GIT_DESCRIBE_CACHE_FILE}" 2>/dev/null
   fi
   unset GIT_DESCRIBE_CACHE_FILE
 else